Spinning nozzle for the production of artificial hollow threads



Oct. 17, 1944. HLZMANN v 2,360,680

AL HOLLOW THREADS SPINNING NOZZLE FOR THE rnonuccriou or ARTIFICI Filed Feb. '12, 1941 II'IIIIIIIIIIIIII Patented 17, 1944 UNITED [STATES PATENT OFFICE I SPINNING? NOZZLE FOR THE PRODUCTION OF ARTIFICIAL HOLLOW THREADS Hermann Holzmann, Hanau-on-the-Main, Germany; vested in the Alien Property Custodian Application February 12, 1941, Serial No. 378,642

2 Claims.

' solid cross section, are known to possess disadvantages over natural threads, e. g., wool threads ,or silk threads, and have particularly less'heat insulating properties, endeavors have been made to produce hollow artificial threads.

' Such efforts, however, have not yet succeeded in .producing, in a technically satisfactory manner, threads having the dimensions of line natural threads of the kind referred to and possessing hollow spaces extending over their whole length.

As fears have heretofore been entertained that the body forming the hollow space, the so-called core, would interfere with the unguided feed of the spinning material intothe nozzle, previous experiments essentially-aimed at ensuring a uni-'. form passage of the spinning material through the nozzle'by a reciprocal movement between the core piece and nozzle. For example, it has been suggested to feed the spinning solution into the hollow spaces forming between two grooved rolls rotating in opposite directions and to insert needles in such hollow spaces with a view of obtain-- ing a hollow shape of the threads forming between the rolls.

Furthermore it has been suggested to reciprocate needles in spinning apertures.

Such methods are impracticable when spinning threads of the small dimensions referred to and, besides, are circumstantial, as they require, above all, a very complicated equipment, nor has one succeeded in producing thereby fine and even hollow threads in a satisfactory manner.

The essential feature of the spinning nomle according to the present invention is that in the apertures of nozzle of otherwise conventional shape and size, having a plurality of bores for the fabrication. of cellulose wool and rayon, hollow space forming cores are provided, preferably in the form of an axially extending wire, or capillary tube, which cores are secured to the inlet of the nozzle aperture or 'proximlty thereof. In'using capillary tubes as hollow space formers which The capillary tubes are either connected to a manifold, e. g., a hollow ring, or singly led out of the nozzle so as to permit air from the outside to be drawn into the nascent-hollow thread or a medium to be blown in or pressed in.

It. is surprising that,merely by inserting, e. g., a solid'wire into the conventional bore of generally extremely narrow cross section by this method of securin the hollow space forming wire to the inlet of the nozzle apertures, a spinning material, such as, e. g., asbestos material, does not stick together in view of such small dimensions of the nozzle area and as a result of the coupling pressures exerted after passing along the wires, nor that the requisite fastening of the hollow space formers either near the nozzle apertures or inside the latter does not result in irregular shapes of the hollow spaces, e. g., by the formation of eddies or deposits.-

The fastening of the hollow space formers, i. e., the wires or capillary tubes, to the inlet of the nozzle apertures aifords the advantage of great simplicity.

Itmust also be taken into consideration that the nozzle apertures with the materials here concerned are practically not discernible with the naked eye and the hollow space forming wires will only be discovered by sumcient magnification, e. g., by means of a microscope.

Since difficulties have been encountered with space forming needles have been adopteidhis proves that it could so much the less be expected that in the case of nomle apertures of, say, -100 my., hollow space forming elements could be fastened at all and become operative.

needles and capillary tubes used as cores yield hollow threads that turn out particularly uniform and, above all, permit of a very economic production of hollow threads.

The accompanying drawing shows a spinning nozzle accordingto the present invention by a number of embodiments.

1 shows a conventional nomle bore with atapering inlet, otherwise of cylindrical shape, such as in common use in spinning nozzles for spinning ordinary rayon.

Fig. 2 shows, in two views displaced by,

degg, a nozzle bore of. conventional design with awireaxiallyinsertedfromtheinletand held at the inlet of the nonle aperture by means of Experience has shown. however, that stationary a transverse wire; the wire forming the hollow space and also the transverse wire may be used in the form of a little cross consisting of one piece.

Fig. 3 shOWS another embodiment of the wire forming the hollow space in the thread.

Fig. 4 shows an embodiment with capillary tube as hollow space former in a longitudinal. section through the nozzle.

Fig. 5.is the top view of a nozzle of this kind on the line TT of Fig. 4.

In particular, (a) designates the wire forming the hollow space in the thread, (b) representing a transverse wire by which the wire (a) is held in centered position. The transverse wire (b) may be fastened simply by pressing its free ends into the nozzle metal. The transverse wire may also be firmly connected, e. g., by being caulked into the nozzle.

When fastening the transverse wire (22) by pressing in, it is recommended to use heat-treatable alloys for the manufacture thereof. In this case the transverse wire is forced in tempered state into the aperture of the untempered nozzle and the latter is then' tempered also. The wires (a) and (b) are suitably made from the. same metal too.

As shown in Figs. 4 and 5, (c) is the'nozzle, (d) the nozzle bore showing a tapering inlet, (e) are the capillary tubes held in position by a holding ring (I) which, in'turn, is held by the nozzle flange and an overlapping cap ring (g), the cap ring with the nozzle flange (h) forming a hollow space outside of the holding ring (I), in which hollow space the lead-in (i) is inserted for blowing in, or pressing in, a suitable medium forming a hollow space or supporting the formation of a hollow space, which medium diffuses in the annular hollow space and is fed from here to the individual capillary tubes.

It has been proved that so simple a fastening method as the one above referred to is absolutely suflicient to hold the wire extending axially in the bore of nozzle and to ensure faultless operation. Other fastening methods may, of course, also be adopted, e. g., by means of two transverse wires.

Another particularly useful fastening method consists in the clamping of both sides of the wire, or capillary tube, forming the hollow space in the thread by means of the material of the nozzle itself; in this case the wire itself is clamped in axial position in the bore of corresponding shape, e. g., by a pressure exerted with a suitable tool upon the inner .nozzle bottom on two oppositesides. Hereby, narrow transverse straps are formed from the material of the nozzle bottom,

which straps hold the Wire in a similar manner as the transverse carrier shown in the drawing.

In certain instances, especially with spinnin nozzles having a very small bore, it is possible to cause the wire forming the hollow space in the thread to'protrude beyond the exterior edge of hole, as is shown in Fig. 3 by Way of example.

When operating the spinning nozzle according to the invention, the spinning solution on entering the bored nozzle surrounds in a similar manner the wire forming-the hollow space in the thread from allsides and evenly. The wire is held in the center of the bore by the streaming viscose and is possibly also forced into axial position when assuming a slightly inclined position.

In this way it is possible to produce artificial hollow threads in the simplest and cheapest manner by conventional spinning nozzles which, by

inserting more or less thin wires, or capillary tubes, into the bores, produce hollow spaces of a particularly desired shape in the thread or permit artificial threads of different shell thickness to be manufactured. The members forming the hollow space in the thread, e. g., Wires of suitable shapes, such as cylindrical, conical shape, or of suitable cross sections, may in the simplest manner be inserted into the bores specially prepared, if desired, and may, if necessary, beinterchanged with comparative ease.

The produced threads possess the advantage that in the case of thinnest threads they have equal outer diameters, but a much lighter weight than solid threads and thus may be made with an appreciably smaller expenditure of material. Besides, they possess the known advantages of hollow threads, in particular the merit of excellent heat insulation.

I claim:

1, Spinning nozzle for the production of artificial hollow filaments from artificial silk or cellulose wool comprising a nozzle body having in its base at least one nozzle opening, a cavityforming core in the nozzle opening affixed closely adjacent to the nozzle opening, and a transverse wire integral with said core connected to said nozzle body at the inlet of the nozzle opening.

2. Spinning nozzle for the production of artificial hollow filaments from artificial silk or cellulose wool comprising a nozzle body having in its base at least one nozzle opening, a cavityforming core in the nozzle opening afflxed closely adjacent to the nozzle opening, the inlet of said nozzle opening tapering outwardly, and a transverse wire integral with said core pressed into the outwardly tapering surface of the nozzle opening.

HERMANN HOLZMANN. 

